The Gaia Hypothesis holds that complex chemistries known as "the living" may play a homeostatic role on a planetary scale, maintaining atmospheric conditions far from an "equilibrium of the dead." Our oxygen-rich Earthian cocktail could never have arisen, nor would be sustained, minus cell-based metabolism.
We humans play a role in the local cybernetics and have evolved new powers to anticipate and counter death threats the dinos never had (e.g. Apophis).
Gus Frederick of Silverton, Oregon shared his hopeful hypothesis that our self-destructive tendencies were symptomatic of species adolescence, a passing phase we'd survive and outgrow. Our long term destiny, thinks Gus, is to spread life extraterrestrially, starting with our moon and Mars.
Only time will tell.
Followup: link to Gus's slides